Resistance of a Wire

To investigate into how the resistance of a wire is affected by the factor of length. The variable in this investigation is the length of the wire.

Strategy:

The equipment was set up as it is in the diagram, the investigation was carried out by taking a 100cm length of wire and measuring the resistance of the wire at different lengths, starting at 0cm, ending at 100cm, in 10 cm intervals. A was used multimeter to measure resistance, and a 100cm ruler was used to measure the length of the wire.

Background Knowledge:

Resistance is caused by current-carrying charged particles hitting stationary atoms that are part of the material that the charged particles are traveling through. Resistance occurs in all objects to a

I used the same piece of wire (36 swg), this is as the resistance of the wire would vary with the thickness of the wire. I used the same ruler, this is as another ruler might have a different measurement system and it may also be more/less accurate than the one I used. I retested, this just cancels out

As the results show, the resistance of a wire is affected by the length of the wire, the results show that as the length of the wire increases, the resistance of the wire increases. This is because the charge has more atoms to hit in the longer length of wire. The results also show that resistance is directly proportional to length. The results also show that the resistance increases by an average of 0.9Ω for every 10 centimetres.

Evaluation

Anomalies:

There are not any real anomalies; the average increase in the resistance every 10 centimetres was 0.9Ω, and there were no major results that were straying off that average increase, there are just a few where the increase is either 1.0Ω or 0.8Ω.

Accuracy:

The results are very accurate, as the measurements of length are only a maximum of 5 mm off the length required, this would not make a difference at all to the resistance of the wire.